A magnetic resonance imaging apparatus (hereinafter, “MRI apparatus” as appropriate) is an apparatus to visualize information inside a subject body into an image, using a nuclear magnetic resonance phenomenon. In the MRI apparatus, data called k-space data is acquired by sampling nuclear magnetic resonance signals from a specific atom (for example, hydrogen atom) present inside an object using coils. Moreover, the MRI apparatus reconstructs a magnetic resonance image (hereinafter, “MR image” as appropriate) by applying the Fourier transform on k-space data.
Nuclear magnetic resonance signals (hereinafter, “MR signals”) are sampled as one-dimensional data. Therefore, to acquire two-dimensional, or three-dimensional reconstruction image, the MR apparatus repeats sampling of one-dimensional data on a k-space, and acquires k-space data necessary for reconstruction. If k-space data is sampled at the same resolution as the MR image (full sampling), reconstruction is enabled by applying the Fourier transform on the acquired k-space data. However, if full sampling is performed in the MRI apparatus, the imaging time is to be considerably long. Accordingly, techniques have been developed conventionally on in both an imaging technique and a reconstruction technique to achieve reduction of the imaging time.
For example, as a reconstruction technique to reduce the imaging time, there is a technique called parallel imaging (hereinafter, “PI” as appropriate) in which multiple coils are used and imaging of a subject body is performed with less samples than full sampling, and an MR image is reconstructed using difference in coil sensitivity of respective coils. As techniques of PI, sensitivity encoding (SENSE) and generalized auto calibrating partially parallel acquisition (GRAPPA) are widely known.